[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 09 of 20] xenpaging: move page add/resume loops into its own function
# HG changeset patch # User Olaf Hering <olaf@xxxxxxxxx> # Date 1321804959 -3600 # Node ID 35a65cd961e7ba04350ce0fe539f677dd4722b93 # Parent 927af61e2c89bf70c3e873140750aa897fb575e9 xenpaging: move page add/resume loops into its own function. Move page resume loop into its own function. Move page eviction loop into its own function. Allocate all possible slots in a paging file to allow growing and shrinking of the number of paged-out pages. Adjust other places to iterate over all slots. This change is required by subsequent patches. v2: - check if victims allocation succeeded Signed-off-by: Olaf Hering <olaf@xxxxxxxxx> diff -r 927af61e2c89 -r 35a65cd961e7 tools/xenpaging/xenpaging.c --- a/tools/xenpaging/xenpaging.c +++ b/tools/xenpaging/xenpaging.c @@ -553,6 +553,27 @@ static int xenpaging_populate_page(xenpa return ret; } +/* Trigger a page-in for a batch of pages */ +static void resume_pages(xenpaging_t *paging, int num_pages) +{ + xc_interface *xch = paging->xc_handle; + int i, num = 0; + + for ( i = 0; i < paging->max_pages && num < num_pages; i++ ) + { + if ( test_bit(i, paging->bitmap) ) + { + paging->pagein_queue[num] = i; + num++; + if ( num == XENPAGING_PAGEIN_QUEUE_SIZE ) + break; + } + } + /* num may be less than num_pages, caller has to try again */ + if ( num ) + page_in_trigger(); +} + static int evict_victim(xenpaging_t *paging, xenpaging_victim_t *victim, int fd, int i) { @@ -596,6 +617,30 @@ static int evict_victim(xenpaging_t *pag return ret; } +/* Evict a batch of pages and write them to a free slot in the paging file */ +static int evict_pages(xenpaging_t *paging, int fd, xenpaging_victim_t *victims, int num_pages) +{ + xc_interface *xch = paging->xc_handle; + int rc, slot, num = 0; + + for ( slot = 0; slot < paging->max_pages && num < num_pages; slot++ ) + { + /* Slot is allocated */ + if ( victims[slot].gfn != INVALID_MFN ) + continue; + + rc = evict_victim(paging, &victims[slot], fd, slot); + if ( rc == -ENOSPC ) + break; + if ( rc == -EINTR ) + break; + if ( num && num % 100 == 0 ) + DPRINTF("%d pages evicted\n", num); + num++; + } + return num; +} + int main(int argc, char *argv[]) { struct sigaction act; @@ -638,7 +683,14 @@ int main(int argc, char *argv[]) return 2; } - victims = calloc(paging->num_pages, sizeof(xenpaging_victim_t)); + /* Allocate upper limit of pages to allow growing and shrinking */ + victims = calloc(paging->max_pages, sizeof(xenpaging_victim_t)); + if ( !victims ) + goto out; + + /* Mark all slots as unallocated */ + for ( i = 0; i < paging->max_pages; i++ ) + victims[i].gfn = INVALID_MFN; /* ensure that if we get a signal, we'll do cleanup, then exit */ act.sa_handler = close_handler; @@ -652,18 +704,7 @@ int main(int argc, char *argv[]) /* listen for page-in events to stop pager */ create_page_in_thread(paging); - /* Evict pages */ - for ( i = 0; i < paging->num_pages; i++ ) - { - rc = evict_victim(paging, &victims[i], fd, i); - if ( rc == -ENOSPC ) - break; - if ( rc == -EINTR ) - break; - if ( i % 100 == 0 ) - DPRINTF("%d pages evicted\n", i); - } - + i = evict_pages(paging, fd, victims, paging->num_pages); DPRINTF("%d pages evicted. Done.\n", i); /* Swap pages in and out */ @@ -689,13 +730,13 @@ int main(int argc, char *argv[]) if ( test_and_clear_bit(req.gfn, paging->bitmap) ) { /* Find where in the paging file to read from */ - for ( i = 0; i < paging->num_pages; i++ ) + for ( i = 0; i < paging->max_pages; i++ ) { if ( victims[i].gfn == req.gfn ) break; } - if ( i >= paging->num_pages ) + if ( i >= paging->max_pages ) { DPRINTF("Couldn't find page %"PRIx64"\n", req.gfn); goto out; @@ -767,25 +808,12 @@ int main(int argc, char *argv[]) /* Write all pages back into the guest */ if ( interrupted == SIGTERM || interrupted == SIGINT ) { - int num = 0; - for ( i = 0; i < paging->max_pages; i++ ) - { - if ( test_bit(i, paging->bitmap) ) - { - paging->pagein_queue[num] = i; - num++; - if ( num == XENPAGING_PAGEIN_QUEUE_SIZE ) - break; - } - } - /* - * One more round if there are still pages to process. - * If no more pages to process, exit loop. - */ - if ( num ) - page_in_trigger(); - else if ( i == paging->max_pages ) + /* If no more pages to process, exit loop. */ + if ( !paging->num_paged_out ) break; + + /* One more round if there are still pages to process. */ + resume_pages(paging, paging->num_paged_out); } else { _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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